Textile material and method of making same



Patented May 14, I940 UNITED STATES TEXTILE MATERIAL AND LIETHOD OF MAKING SAME Cyril M. Croft, Cumberland, Md., assignor to Celanese Corporation of America, a corporation of Delaware No Drawing. Application April 6, 1938, Serial No. 200,433

6 Claims.

This invention relates to the treatment of fabrics, yarns, filaments and like textile materials containing an organic ester of cellulose with a saponifying agent to obtain fabrics, yarns and filaments having an afiinity for acid and basic dyestuffs employed in dyeing and printing cotton fabrics which dyestuffs have little or no aflinity for organic derivative of cellulose material.

An object of the invention is the saponification of fabrics, particularly those formed from yarns containing an organic ester of cellulose, which yarns have a high degree of twist or offer resistance to the penetration of fluid treating mediums for other reasons. Other objects of this inventiop will appear from the following detailed description.

It is known that fabrics formed from organic esters of cellulose yarns may be saponified by treatment with a base or a basic salt and that such saponified fabrics develop an afiinity for cotton dyestuffs depending upon the extent of saponification and upon the type of saponiflcation treatment. For the purpose of producing cellulose acetate fabrics to be dyed or printed with cotton dyestuffs (direct dyeing acid or vat dyestuffs), it is customary to saponify a cellulose acetate fabric until there is a weight loss of from 10 to 15% although lesser and greater weight losses are regularly effected, say from 5 to 20% or more. In methods employed prior to my invention, only certain types of fabric, i. e. those which are readily penetrated by the saponification fluid,- could be saponified, especially on a winch. Other types of fabrics, when dyed, were blotchy or streaked ,due to uneven s'aponification or non-uniform type of saponification. For instance, great difficulty was experienced in uniformly saponifying crepe fabrics formed of highly twisted (about turns per inch) yarn and closely woven taffetas and satins. I have found that crepe fabrics and other fabrics normally diflicult to penetrate with saponifying bath's may be uniformly saponified by adding pine oil to the saponifying bath.

Another advantage of this invention is that any type of saponification may be produced. The speed of saponification, among other things, controls the type of saponification, i. e. whether the saponification is limited to the surface of the filaments or fibers that make up the yarn, or whether the saponification is through and through saponification. Prior to this invention it was necessary to treat crepe fabrics, tafietas and satin fabrics with a slow saponifying bath for long periods of time to obtain uniform saponification. This resulted in a low dye aflinity change per weight loss. Long saponification treatments not only produce a through and through'type of saponification, which is not always desired, but also are likely to be injurious to the fabric, especially when treating crepe fabrics prior to their treatment in creping baths. However, I have found that with the use of pine oil in the bath it is not necessary to saponify slowly by cooling the bath and/or diluting the concentration of effective saponifying agents to obtain a uniform saponification. By employing this invention, uniform saponification may be obtained employing more concentrated effective saponifying agents, thus greatly reducing the time of treatment of the fabric in the bath.

In accordance with my invention, I saponify fabrics or other textile materials made of or containing an organic ester of cellulose by treating the same with a bath containing pine oil and a saponifying agent such as alkali, or ammonia hydroxides or carbonates, or organic ammonium or amine compounds having saponifying properties, or inorganic or organic salts having a saponifying action. Examples of suitable saponifying agents are sodium, potassium or ammonia hydroxide, carbonate or acetate; dior tri-ethanolamine; secondary and tertiary alkyl substituted ammonium compounds, etc. The degree of saponification may be from less than 3% by weight loss to substantially complete saponification. However, the invention is particularly applicable to saponification which eifects a weight loss of from 5 to 20%, based upon the weight of the organic ester of cellulose in the fabric, and to a quick saponification which greatly modifies the surface of the filaments and leaves the center of the filaments substantially unchanged. This produces a fabric having an afiinity for cotton dyestuffs yet one which retains to a. great extent the thermoplastic properties of the derivative of cellulose and which retains the original properties of the fabric with respect to beauty of drape, luster, hand, etc.

This invention is applicable to textile materials such as fabrics,'yarns, etc., that are made of or contain organic esters of cellulose. Examples of organic esters of cellulose are cellulose acetate, cellulose formate, cellulose propionate and cellulose butyrate. Fabrics may be made entirely of yarns containing organic esters of cellulose or they may be formed from such yarns together with yarns of other materials such as reconstituted or regenerated cellulose, cotton, wool,

silk, etc. The invention is of especial importance in the saponification of crepe fabrics which may contain, besides the organic ester of cellulose threads, threads of regenerated or reconstituted cellulose. These may alternate in any desired manner to produce the crepe effect desired.

A fabric formed of substantially all organic ester of cellulose yarns may be saponifled by cmploying a winch, the treating bath of which may comprise from 1 to 20 or more times the weight of thefabric of water containing from 5 to 20% or more, based on the weight of the fabric, of a saponifying agent equivalent in strength to that of sodium hydroxide. This aqueous bath also contains from 0.5 to 2 grams per liter of pine oil. The time and temperature of the bath may be so regulated to give the desired degree and type of saponification. The pine oil in the bath prevents the fabric from floating andalso effects a rapid penetration of the saponifying agent into the interstices of the fabric. Although one or more grams per liter of soap may be employed, it is pref erable to use only the pine oil as the penetrating agent as soap tends to froth and prevent the fabric from sinking. The floating of the fabric, due to the froth formed when employing soap, tends to create a blotchy pattern and warn streaks where the saponifying agent has not had a chance to act upon the fabric for the same length of time as that part of the fabric which is not caused to float.

As an illustration of my invention, but without being limited thereto, the following example is given:

Example 100 pounds of fabric made by weaving yarns of cellulose acetate twisted to turns per inch is treated on the winch with a bath containing 25 gallons of water, 12 pounds of sodium carbonate and 1 gram per liter of pine oil. The fabric is treated at room temperature for two hours, ef-

fecting a weight loss to the fabric of between 10 and 15%. The fabric is dyed with a cotton dyeing dyestufi and the fabric thus dyed is of uniform color, free of blotchiness and warp streaks pro duced by uneven dye affinity.

It is to be understood that the foregoing detailed description is merely given by way of illustration and that many variations may be made therein without departing from the spirit of my invention.

Having described my invention, what I desire to secure by Letters Patent is:

1. In a process-of saponifying textile materials containing an organic ester of cellulose, the steps of subjecting the fabric to a saponifying bath consisting of a saponifying agent and pine oil.

2. In a process of saponifying textile materials containing cellulose acetate, the steps of subjecting the fabric to a saponlfying bath consisting of a saponifying agent and pine oil.

3. In a process of saponifying textile materials containing an organic ester of cellulose, the steps of subjecting the fabric to a saponifying bath consisting of a saponifying agent and 0.5 to 2 grams per liter of pine oil.

4. In a process of saponifying textile materials containing cellulose acetate, the steps of subjecting the fabric to a saponifying bath consisting of a saponifying agent and 0.5 to 2 grams per liter of pine oil.

5. In a process of saponifying textile materials containing cellulose acetate, the steps of subjecting the fabric to a saponifying bath consisting of sodium carbonate and pine oil.

I 6. In a process of saponifying textile materials containing cellulose acetate, the steps of subjecting the fabric to a saponifying bath consisting of sodium carbonate and 0.5 to 2 grams per liter of pine oil.

CYRIL M. CROFT. 

